EP1114311A1 - Controle des proprietes d'evacuation de la chaleur d'une surface assurant un transfert thermique - Google Patents

Controle des proprietes d'evacuation de la chaleur d'une surface assurant un transfert thermique

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Publication number
EP1114311A1
EP1114311A1 EP99934972A EP99934972A EP1114311A1 EP 1114311 A1 EP1114311 A1 EP 1114311A1 EP 99934972 A EP99934972 A EP 99934972A EP 99934972 A EP99934972 A EP 99934972A EP 1114311 A1 EP1114311 A1 EP 1114311A1
Authority
EP
European Patent Office
Prior art keywords
heat
temperature
test conduit
liquid
test
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Withdrawn
Application number
EP99934972A
Other languages
German (de)
English (en)
Inventor
Norman Foster Glen
Jeffery Harry Howarth
Andrew Mark Jenkins
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
TUV Sud Services UK Ltd
Original Assignee
TUV Sud Services UK Ltd
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by TUV Sud Services UK Ltd filed Critical TUV Sud Services UK Ltd
Publication of EP1114311A1 publication Critical patent/EP1114311A1/fr
Withdrawn legal-status Critical Current

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Classifications

    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
    • G01N25/00—Investigating or analyzing materials by the use of thermal means
    • G01N25/18—Investigating or analyzing materials by the use of thermal means by investigating thermal conductivity

Definitions

  • This invention relates to monitoring, and relates more particularly but not exclusively to monitoring the effects of fouling in fluid-carrying thermal transfer arrangements, eg heat exchangers.
  • Heat exchangers containing flowing fluids are widely employed throughout industry in (for example) the food processing industries, the chemical industry, pharmaceuticals, etc. Heat exchanger surfaces in contact with liquids are liable to progressive fouling due to corrosion, biological growth, deposits, and other reasons. Notwithstanding anti-fouling measures such as mechanical cleansing of surfaces and dosing of liquids with biocides, fouling usually progresses to such an extent as seriously to degrade heat transfer through the fouled surfaces.
  • Fouling of heat exchangers in process plant is so ubiquitous that the fouling allowance in the calculation of heat exchanger surface area is a firmly established aspect of design.
  • the practice of estimating the size of this allowance is, however, far from ideal, often relying on unattributed tabulated values of R f (thermal fouling resistance). This causes unnecessary inefficiency in affected industries resulting from oversizing of plant and equipment, lost production due to scheduled and unscheduled downtime, and from energy losses due to increased thermal inefficiency and pressure drop.
  • Another approach has involved research into mathematical modelling of fouling for the purpose of predicting the rate and cleanability of fouling, and determination of optimum cleaning schedules. Progress is hindered due to the complexities of process stream properties interacting with frequently unknown flow and surface characteristics.
  • the present invention provides a fouling monitor for use in industrial plant which overcomes many of the problems of previous devices by providing a self- contained unit with on-board data processing and an output signal directly proportional to R f (thermal fouling resistance).
  • liquid comprises true liquids and liquid-like fluent materials, eg slurries, soups, suspensions, etc.
  • a monitoring method for monitoring the heat transfer properties of a heat transferring surface forming part of a containment for a flowing liquid comprising the steps of diverting a representative fraction of the flowing liquid through a test conduit selected to be an analogue of the heat transferring surface, causing a determined heat flow to pass through the wall of the test conduit between the fraction of flowing liquid passing through the test conduit and a heat source or sink means external to the test conduit, measuring the rate of flow of liquid through the test conduit, measuring selected temperatures and/or temperature differentials at selected locations, and calculating the heat transfer properties of the test conduit on the basis of the measurements to provide an analogue of the heat transferring properties of the heat transferring surface.
  • the method preferably comprises the step of measuring the temperature differential in the liquid flowing through the test conduit, between liquid upstream of the heat source or sink means and liquid downstream of the heat source or sink means.
  • the method preferably also comprises the step of determining the temperature differential between inner surface of the wall of the test conduit and the bulk temperature of the liquid in a region of the test conduit through which the heat flow passes between the liquid and the heat source or sink means.
  • monitoring apparatus for monitoring the heat transfer properties of a heat transferring surface forming part of a containment for a flowing liquid
  • the monitoring apparatus comprising a test conduit selected to be an analogue of the heat transferring surface, diversion means for diverting a representative fraction or sidestream of the flowing liquid through the test conduit, a heat source or sink means external to the test conduit and thermally coupled thereto, flow rate measuring means for measuring the rate of flow of liquid through the test conduit, temperature measuring means for measuring selected temperatures and/or temperature differentials at selected locations, and calculating means for calculating the heat transfer properties of the test conduit on the basis of the measurements to provide an analogue of the heat transferring properties of the heat transferring surface.
  • the temperature measuring means preferably comprises means for determining the temperature increase or decrease of the liquid passing through the test conduit caused by operation of the heat source or sink means; the temperature differential determining means may operate either by utilising a differential measurement technique or by separately measuring the temperatures of the liquid upstream and downstream of the heat source or sink means, and subtracting one temperature from another.
  • the temperature measuring means preferably also comprises means for determining the temperature differential between the inner surface of the wall of the test conduit and the bulk temperature of the liquid in the vicinity of the heat source or sink means; the temperature differential determining means may operate either by utilising a differential measurement technique or by separately determining the inner surface temperature and the average fluid temperature within the test conduit, and then subtracting one temperature from the other.
  • Fig 1 is an overall schematic diagram of a preferred embodiment of monitoring apparatus.
  • Fig 2 is a schematic diagram of part of the apparatus of Fig 1.
  • FIG 1 this is a schematic representation of a monitoring arrangement 10 installed on a pipeline 12 which is carrying a stream of liquid whose effect on a downstream heat exchanger (not shown) is to be monitored by the arrangement 10.
  • a liquid diverter 14 which may simply be a side-branch whose bore is small relative to that of the pipeline 12, taps a small but adequate portion of the liquid flow along the pipeline 12 and diverts the tapped portion of flowing liquid into and through the monitoring arrangement 10. (Treatment of the tapped liquid within the monitoring arrangement 10 will be detailed below) .
  • the tapped liquid can be returned to the pipeline 12 by means of a further side-branch 16 downstream of the diverter 12, or the tapped liquid can be jettisoned to a drain 18.
  • the portion of flowing process liquid tapped by the diverter 14 to run through the monitoring arrangement is small relative to the total flow of process liquid along the pipeline 12, the tapped portion is adequate to ensure that the tapped portion is a representative fraction of the flowing process liquid.
  • the representative fraction of liquid tapped by the diverter 14 passes along a test conduit 20 formed of the same material as the downstream heat exchanger and having the same wall thickness.
  • the test conduit 20 is part of a flow module 22 contained within the monitoring arrangement 10.
  • the flow module 22 also contains other components and sub-assemblies which will now be detailed with reference to Fig 2.
  • FIG 2 this schematically illustrates the arrangement within the flow module 22 of the test conduit 20 and of the other components and sub- assemblies.
  • the latter comprise a valve or other suitable flow control device 24 for regulation of the volumetric rate of liquid flow through the test conduit 20 as measured by a flowmeter or other suitable flow measurement device 26.
  • a block 28 of metal or other material of good thermal conductivity Surrounding part of the test conduit 20 within the flow module 22 is a block 28 of metal or other material of good thermal conductivity. Thermally coupled to the block 28 is a heat source and/or sink 30 of any suitable form.
  • the heat source and/or sink 30 could, for example, be a coiled pipe carrying a heated or chilled fluid, an electrically powered resistive heating element, an array of Peltier units, or any other suitable means by which a controlled heat flow can be applied to the test conduit 20, ie by which heat can be supplied to or extracted from the test conduit 20 at a known rate so as to model the thermal conditions pertaining to the downstream heat exchanger.
  • a first temperature sensor 32 is embedded in the block 28 slightly beyond the outer surface of the test conduit 20 such that the sensor 32 measures a temperature from which the inner surface temperature of the test conduit 20 can be derived at a location where the conduit 20 is surrounded by the block 28. This arrangement of the temperature sensor 32 enables the inner surface temperature of the test conduit 20 to be derived.
  • a second temperature sensor 34 measures the temperature of the liquid flowing through the test conduit 20, at a location immediately upstream of the block 28.
  • a third temperature sensor 36 measures the temperature of the liquid flowing through the test conduit 20, at a location immediately downstream of the block 28.
  • the temperature sensors 34 and 36 can be arranged to measure absolute temperatures, or they can be jointly arranged so to as measure the difference in liquid temperatures between upstream and downstream sides of the block 28, ie so as to measure the increase or decrease in liquid temperature brought about by operation of the heat source and/or sink 30. If a differential technique is used, an additional temperature sensor must be used to measure the absolute temperature of the liquid flowing through the test conduit 20 at a defined location between the differential measurement points (for example at the location of the upstream temperature sensor 34).
  • the temperature differential between the inner surface of the wall of the test conduit 20 and the bulk temperature of the liquid between upstream and downstream sides of the block 28 can be determined from the temperatures measured by the temperature sensors 32, 34 and 36.
  • sensor 32 can be replaced with a differential measurement technique consisting of one sensor within the liquid and one within the test conduit wall, between the upstream and downstream sides of the block 28, from which the temperature differential can be determined.
  • an instrumentation signal processing and control module 38 Also contained within the monitoring arrangement 10, but outwith the flow module 22, are an instrumentation signal processing and control module 38, and a power supply module 40.
  • the module 38 contains a data analysis and storage unit (not shown per se) or other suitable means by which flow rate signals from the flow measurement device 26 and temperature dependent signals from the temperature sensors 32, 34 and 36 are monitored and processed to produce a calculated thermal fouling resistance R f for the surface in contact with the liquid flowing through the test conduit 20, as well as operating the flow control device 24 to control the rate of flow of tapped process liquid through the test conduit 20, and regulating operation of the heat source and/or sink 30 to ensure a desired rate of heat flux, ie a desired rate of heat supply to or heat extraction from the test conduit 20 and the liquid flowing therethrough.
  • the power supply module 40 contains equipment necessary to receive mains electric power and to deliver power at the lower voltage(s) required by the instrumentation, signal processing and control module 38 and by such devices (eg the flow control device 24) as may draw power from the module 38. If the heat source and/or sink 30 is electrically operated, the necessary power must also be supplied by the module 40 under the control of the module 38.
  • Each of the modules 22, 38 and 40 has a respective housing which is waterproof to an appropriate standard (for example Standard "IP65”), and which can be locked shut to guard against tampering.
  • IP65 Standard
  • the data analysis and storage unit within the module 38 registers a zero flow rate signal from the flow measuring device 26 (or an excessively low flow rate), operation of the heat source and/or sink 30 is interrupted until adequate flow is resumed. Similarly, if the data analysis and storage unit registers temperature signals from the temperature sensors 32, 34 and 36 which are excessively high or low (depending on whether the device 30 is being used as a heat source or as a heat sink), operation of the heat source and/or sink 30 is interrupted. Additionally or alternatively, there may be one or more independent devices for protection against over-temperature or under- temperature.
  • Sidestream monitoring takes a side stream of a fluid from a process stream and passes it through an appropriately instrumented test section.
  • the fluid is either returned to the process or run to drain.
  • the monitor detects change in heat transfer in the test section subjected to an applied heat flux due to fouling, corrosion or erosion of the surface in contact with the fluid flowing through the test section.
  • test section simulates the temperature and heat flux (for a heat transfer application), the geometry and fluid flow for the application under test.
  • the technique used can simulate heat transfer or isothermal applications, use any geometry of flow channel and test any fluid.
  • the test section may consist of a single test section or multiple sections connected in series or parallel.
  • the material of the test section may be the same as that of a specific unit in the process being tested, or not, as appropriate;
  • the flow geometry consists of any flow path/channel geometry required to simulate the fluid flow of a specific unit in the process being tested (and may be, but is not limited to, cylindrical, flat or corrugated plate, spiral or extended surfaces); • a method is provided for applying or removing a quantity of heat from the fluid under test either by supplying heat by an appropriate means (including, but not limited to, electrical resistance heaters, steam or other heat transfer fluid, induction heating) or by removing heat using a cooling coil;
  • an appropriate means including, but not limited to, electrical resistance heaters, steam or other heat transfer fluid, induction heating
  • the deterioration in heat transfer as a function of time is determined at any given time by
  • the rate of heat flow is determined from
  • n mass flow rate of fluid through test section
  • C p specific heat capacity of test fluid
  • ⁇ T temperature difference between fluid at inlet to and outlet from test section.
  • the mass flow rate of the fluid can be determined by direct measurement with a mass flow meter or calculated from the known dimensions of the test section and the density of the test fluid if a volumetric or superficial velocity flow meter is used. If an indirect measurement method is used the data analysis and storage unit shall be capable of processing the signal produced from such a meter, plus any other required signals and information (such as fluid temperature, variation of fluid density with temperature) to produce a mass flow rate.
  • the change in temperature of the test fluid across the test section must be measured to sufficient accuracy and with sufficient resolution to allow values of R f to be calculated to ⁇ lxlO "5 square metre degree Kelvin per watt. This may be achieved either by direct measurement of the temperature difference using, for example, a differential thermocouple or thermopile assembly or indirectly by measuring the inlet and outlet fluid temperature and calculating the difference.
  • the mean temperature of the fluid in the test section must also be measured with sufficient accuracy to allow the data analysis and storage unit to calculate required thermophysical properties of the fluid including density, viscosity and heat capacity.
  • the mean temperature of the wall of the test section in contact with the test fluid must be measured with sufficient accuracy and with sufficient resolution to allow values of R f to be calculated to ⁇ lxlO "5 square metre degree Kelvin per watt.
  • multiple sensors may be required and the data storage and analysis unit may have to calculate a representative value.
  • a signal representative of the mean temperature of the wall of the test section in contact with the test fluid must be sent to the unit used to control the rate of heat flow to or from the test section.
  • the film heat transfer coefficient £ for the fluid in contact with the wall of the test section will be a function of temperature and fluid velocity and hence the apparent overall heat transfer coefficient U of the test section will vary even in the absence of any deterioration due to fouling, corrosion or erosion.
  • U 0 must be the reference heat transfer coefficient at time t 0 corresponding to the temperature and fluid velocity conditions pertaining at time t. This can be achieved by using a function to calculate the effects of temperature and fluid velocity on the heat transfer coefficient. For forced- convection heat transfer in turbulent pipe flow, the general form of this function is
  • the form of the equation (additional factors to account for viscous fluids, short flow passage correction terms etc) and the values of the constants depend on the specific application.
  • the data analysis and storage unit must therefore be capable of processing any received signals and information (such as fluid temperature and flow rate, variation of fluid properties with temperature) to calculate an appropriate reference heat transfer coefficient U 0 using a form of equation (4) specific to the geometry, fluid and flow conditions pertaining in the test section.
  • the principle of operation is such that any change in heat transfer in the test section (corrected for fluid velocity effects) will be detected, whether caused by fouling, corrosion, erosion or any combination thereof.
  • the technique is not specific to one particular form or mechanism of fouling but will detect any change in heat transfer in the test section caused by any fouling mechanism or combination of mechanisms.
  • Each of the sensors (flow meter, temperature sensors) must be calibrated as must all parts of the signal processing assembly. In addition to individual calibration of sensors it may be necessary to calibrate complete functional groups (including, for example, the sensors used to measure the change in temperature of the test fluid across the test section).
  • each test section must be calibrated across the full range of conditions at which it will operate. Under clean fluid conditions a series of measurements are made at fluid velocities covering the required range. Clean heat transfer coefficients are then calculated from equations (1) and (3) and a plot of 1/U against 1/Re n produced from which the reference heat transfer coefficient may then be calculated.
  • All the sensors and signal processing assembly must be sufficiently stable such that over the period required to detect a meaningful change in R f sensor or instrument drift does not cause unacceptable errors in R f .
  • the function of the data analysis and storage unit is to take the raw data measured by the sensors (temperatures and/or temperature differences and flow rate) and process it to provide a calculated thermal fouling resistance R f and make the value available in a convenient form.
  • the data analysis and storage unit therefore provides -
  • the program controlling the operation of the data analysis and storage unit may be required to perform additional tasks including, but not limited to, periodic automation calibration to determine residual thermal offsets in ⁇ T and ⁇ T and storage, processing and outputting of data from additional sensors which may be incorporated into the monitor (such as pressure/differential pressure measuring devices, pH and conductivity meters, general or species-specific biological activity meters).
  • additional sensors such as pressure/differential pressure measuring devices, pH and conductivity meters, general or species-specific biological activity meters.
  • the monitor in particular its output R f signal, can be used in a number of ways, including but not limited to :-
  • the fouling monitor is a sidestream monitor which uses the technique outlined above with the following specific features and optional alternatives:
  • test section(s) which may be made from the same material as the specific heat exchanger being monitored; • aqueous fluids flowing through the test section(s);
  • the heat exchanger was described as being downstream of the monitoring arrangements 20.
  • the monitoring arrangement is not necessarily upstream of the heat exchanger since conditions of access, plant operation, or other considerations may require the monitoring arrangement to be downstream of the heat exchanger.
  • test conduit 20 was formed of the same material as the downstream heat exchanger, and had the same wall thickness.
  • the test conduit material is not necessarily the same as the last heat exchanger, and the wall thickness of the test conduit is irrelevant, since the technique of the invention isolates the effects of fouling on the inner surface only.
  • test conduit 20 While the bore of the test conduit 20 is preferably selected such that the test conduit is an analogue of the heat exchanger, it may be desirable or necessary to substitute a tube of a different bore, and then to scale the monitoring results on the basis of Reynolds number so as to give hydrodynamic equivalence.

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  • Physics & Mathematics (AREA)
  • Health & Medical Sciences (AREA)
  • Life Sciences & Earth Sciences (AREA)
  • Chemical & Material Sciences (AREA)
  • Analytical Chemistry (AREA)
  • Biochemistry (AREA)
  • General Health & Medical Sciences (AREA)
  • General Physics & Mathematics (AREA)
  • Immunology (AREA)
  • Pathology (AREA)
  • Investigating Or Analyzing Materials Using Thermal Means (AREA)

Abstract

La présente invention concerne un procédé de contrôle des propriétés d'évacuation de la chaleur d'une surface qui fait partie de l'enceinte de containement d'un liquide en circulation et qui assure un transfert thermique. Ce procédé de contrôle consiste à : détourner une fraction représentative du liquide en circulation par un conduit d'essai (20) choisi pour son analogie avec la surface de transfert thermique; évacuer une quantité déterminée de chaleur au travers de la cloison du conduit, entre la fraction de liquide traversant ce conduit et une source ou un diffuseur de chaleur situé à l'extérieur de ce même conduit; mesurer le débit de liquide dans le conduit d'essai; relever certaines températures ou certains différentiels de température en des points déterminés; et, à partir de ces relevés, calculer les propriétés de transfert thermique du conduit d'essai et, par analogie, les caractéristiques thermiques de la surface assurant le transfert de chaleur. L'invention s'attache également à décrire le dispositif correspondant.
EP99934972A 1998-07-28 1999-07-26 Controle des proprietes d'evacuation de la chaleur d'une surface assurant un transfert thermique Withdrawn EP1114311A1 (fr)

Applications Claiming Priority (3)

Application Number Priority Date Filing Date Title
GBGB9816304.1A GB9816304D0 (en) 1998-07-28 1998-07-28 Monitoring
GB9816304 1998-07-28
PCT/GB1999/002428 WO2000007000A1 (fr) 1998-07-28 1999-07-26 Controle des proprietes d'evacuation de la chaleur d'une surface assurant un transfert thermique

Publications (1)

Publication Number Publication Date
EP1114311A1 true EP1114311A1 (fr) 2001-07-11

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Application Number Title Priority Date Filing Date
EP99934972A Withdrawn EP1114311A1 (fr) 1998-07-28 1999-07-26 Controle des proprietes d'evacuation de la chaleur d'une surface assurant un transfert thermique

Country Status (4)

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EP (1) EP1114311A1 (fr)
AU (1) AU5058599A (fr)
GB (1) GB9816304D0 (fr)
WO (1) WO2000007000A1 (fr)

Families Citing this family (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
NL1033227C2 (nl) * 2007-01-15 2007-08-01 Groenholland B V Methode en apparaat voor het meten van de effectieve warmteoverdracht in een systeem met vloeistofcircuit.
US8609429B2 (en) 2010-11-17 2013-12-17 Exxonmobil Research And Engineering Company Methods for identifying high fouling hydrocarbon and for mitigating fouling of process equipment
US9404847B2 (en) * 2010-11-17 2016-08-02 Exxonmobil Research And Engineering Company Methods for mitigating fouling of process equipment
CN111948251A (zh) * 2020-08-21 2020-11-17 中国工程物理研究院材料研究所 一种用于热流测试的新型平台结构
CN113791115B (zh) * 2021-09-15 2023-10-20 湘潭大学 一种板式换热器传热性能测试方法及装置
CN118113537B (zh) * 2024-04-30 2024-07-05 山东工程职业技术大学 一种计算机的稳定性测试方法和装置

Family Cites Families (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR2426255A1 (fr) * 1978-05-19 1979-12-14 British Petroleum Co Procede pour detecter et mesurer la tendance a l'encrassement d'un liquide chauffe
DE3136225A1 (de) * 1980-10-30 1982-06-16 Drew Chemical Corp., Boonton, N.J. Verfahren und vorrichtung zum pruefen von fluiden
US4396300A (en) * 1981-05-01 1983-08-02 Bridger Scientific, Inc. Method and apparatus for determining the heat transfer characteristics of a tube
GB9104195D0 (en) * 1991-02-28 1991-04-17 Eden Robert D Fouling probe

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
See references of WO0007000A1 *

Also Published As

Publication number Publication date
GB9816304D0 (en) 1998-09-23
AU5058599A (en) 2000-02-21
WO2000007000A1 (fr) 2000-02-10

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